The present invention relates generally to rotary regenerative heat exchangers. More particularly, the present invention relates to heat exchange baskets, which contain heat absorbent material, for rotary regenerative heat exchangers.
A rotary heat exchanger is employed to transfer heat from one hot gas stream, such as a flue gas stream, to another cold gas stream, such as combustion air. The rotor contains a mass of heat absorbent material which is first positioned in a passageway for the hot gas stream where heat is absorbed by the heat absorbent material. As the rotor turns, the heated absorbent material enters the passageway for the cold gas stream where the heat is transferred from the absorbent material to the cold gas stream.
In a typical rotary heat exchanger, such as a rotary regenerative air preheater, the cylindrical rotor is disposed on a vertical central rotor post and divided into a plurality of sector-shaped compartments by a plurality of radial partitions or diaphragms extending from the rotor post to the outer peripheral shell of the rotor. These sector-shaped compartments are loaded with heat exchange baskets which contain the mass of heat absorbent material commonly comprised of stacked plate-like elements.
In many conventional horizontal rotary heat exchangers having full sector heat exchange baskets, the baskets are attached to the rotor by a formed flange. The formed flange is bent to an included angle of less than 90.degree. and has one end portion mounted to the side of the basket and another end portion which is bolted to a shell bar. The flange is subjected to high bending stresses and to fatigue loading as the rotor rotates and is therefore subject to failure later in life. The nature of the formed flange design does not allow for the optimization of frontal area for heat transfer surface. Installation of shell bars for mounting the full sector heat exchange baskets, along with the associated gussets and filler pieces to reduce bypass flow, is very time consuming either in the manufacture of a new rotor, or the modification of an existing rotor.